Modeling - Field Sampling: Principles and Practices in Environmental Analysis - page 196

“holes” in the compacted layer is not known. Even when the holes and their positions are
know they are hard to model. The figures shown are black and white; however, most if
not all computer modeling software will present these types of results in color. Different
colors will be used to show the concentration of the components of interest in various
locations. A color scale with reference will also be provided. Some common commercial
computer modeling programs are given in Table 7.3.
In developing a field sampling plan these models can help in directing sampling efforts
to areas with the greatest likelihood of being contaminated. Another way to use these is in
presentations designed to justify sampling plans and procedures to regulatory agencies.
The data can also be presented in a way that local populations can easily understand.
FIGURE 7.15 Model of contaminant through soil with a compacted layer.
Note that the contamination has moved through a “hole” in the
compacted layer and is contaminating lower layers.
7.8. GIS AND ENVIRONMENTAL MODELING
Because the Geographic Information System (GIS) is a powerful tool for relating and
displaying areas on and in the Earth, it has been proposed that it can be used in
environmental modeling. Some developments along these lines have been made, but GIS
is still used to display the environment as it is presently. It thus does not have predictive
capabilities, which are an important component of environmental modeling. By
displaying environmental conditions over a period of time, however, trends in the
movement of pollution or changes in the quality of the environment can be seen and